use node-pikaday from system

debian/control

@@ -318,6 +318,7 @@ Depends: ${shlibs:Depends}, ${misc:Depends}, ruby | ruby-interpreter,
  node-jszip-utils,
  node-marked,
  node-mousetrap,
+ node-pikaday,
  node-raw-loader,
  node-stats-webpack-plugin,
  node-three,

debian/patches/0420-use-system-libs.patch

@@ -1,6 +1,6 @@
 --- a/package.json
 +++ b/package.json
-@@ -12,60 +12,28 @@
+@@ -12,60 +12,27 @@
      "webpack-prod": "NODE_ENV=production webpack --config config/webpack.config.js"
    },
    "dependencies": {
@@ -36,7 +36,7 @@
      "monaco-editor": "0.8.3",
 -    "mousetrap": "^1.4.6",
      "name-all-modules-plugin": "^1.0.1",
-     "pikaday": "^1.5.1",
+-    "pikaday": "^1.5.1",
      "prismjs": "^1.6.0",
      "raphael": "^2.2.7",
      "raven-js": "^3.14.0",

debian/patches/0430-remove-devdeps.patch

@@ -1,6 +1,6 @@
 --- a/package.json
 +++ b/package.json
-@@ -36,25 +36,5 @@
+@@ -35,25 +35,5 @@
      "webpack-bundle-analyzer": "^2.8.2"
    },
    "devDependencies": {